<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <div id="app">
    <div>
      <div style="display: inline-block" v-for="(item, index) in arr">
        <input type="checkbox" :value="item" v-model="checkedItems">
        <span>{{ item }}</span>
      </div>
      <p>你选中的元素, 累加的值和为: {{ total }}</p>
    </div>
  </div>
  <script src="../js/vue.js"></script>
  <script>
    const app = new Vue({
      el: '#app',
      data: {
        arr: [9, 15, 19, 25, 29, 31, 48, 57, 62, 79, 87],
        checkedItems: []
      },
      computed: {
        total() {
            console.log(JSON.stringify(this.checkedItems));
            
          return this.checkedItems.reduce((sum, value) => sum + value, 0);
        }
      }
    });
  </script>
</body>

</html>